diff --git a/akka-cluster/src/main/scala/akka/cluster/Reachability.scala b/akka-cluster/src/main/scala/akka/cluster/Reachability.scala
index dd9f61e666..b895ee1fb7 100644
--- a/akka-cluster/src/main/scala/akka/cluster/Reachability.scala
+++ b/akka-cluster/src/main/scala/akka/cluster/Reachability.scala
@@ -158,11 +158,14 @@ private[cluster] class Reachability private (
       (this.observerRows(observer), other.observerRows(observer)) match {
         case (None, None) ⇒
         case (Some(rows1), Some(rows2)) ⇒
-          mergeObserverRows(allowed, rows1, rows2, observerVersion1, observerVersion2, recordBuilder)
+          val rows = if (observerVersion1 > observerVersion2) rows1 else rows2
+          recordBuilder ++= rows.collect { case (_, r) if allowed(r.subject) ⇒ r }
         case (Some(rows1), None) ⇒
-          recordBuilder ++= rows1.collect { case (_, r) if r.version > observerVersion2 && allowed(r.subject) ⇒ r }
+          if (observerVersion1 > observerVersion2)
+            recordBuilder ++= rows1.collect { case (_, r) if allowed(r.subject) ⇒ r }
         case (None, Some(rows2)) ⇒
-          recordBuilder ++= rows2.collect { case (_, r) if r.version > observerVersion1 && allowed(r.subject) ⇒ r }
+          if (observerVersion2 > observerVersion1)
+            recordBuilder ++= rows2.collect { case (_, r) if allowed(r.subject) ⇒ r }
       }
 
       if (observerVersion2 > observerVersion1)
@@ -174,31 +177,6 @@ private[cluster] class Reachability private (
     new Reachability(recordBuilder.result(), newVersions)
   }
 
-  private def mergeObserverRows(
-    allowed: immutable.Set[UniqueAddress],
-    rows1: Map[UniqueAddress, Reachability.Record], rows2: Map[UniqueAddress, Reachability.Record],
-    observerVersion1: Long, observerVersion2: Long,
-    recordBuilder: immutable.VectorBuilder[Record]): Unit = {
-
-    val allSubjects = rows1.keySet ++ rows2.keySet
-    allSubjects foreach { subject ⇒
-      if (allowed(subject)) {
-        (rows1.get(subject), rows2.get(subject)) match {
-          case (Some(r1), Some(r2)) ⇒
-            recordBuilder += (if (r1.version > r2.version) r1 else r2)
-          case (Some(r1), None) ⇒
-            if (r1.version > observerVersion2)
-              recordBuilder += r1
-          case (None, Some(r2)) ⇒
-            if (r2.version > observerVersion1)
-              recordBuilder += r2
-          case (None, None) ⇒
-            throw new IllegalStateException(s"Unexpected [$subject]")
-        }
-      }
-    }
-  }
-
   def remove(nodes: Iterable[UniqueAddress]): Reachability = {
     val nodesSet = nodes.to[immutable.HashSet]
     val newRecords = records.filterNot(r ⇒ nodesSet(r.observer) || nodesSet(r.subject))